<template>
<div class="home-page">

  <div class="banner">
    <div class="container">
      <h1 class="logo-font">conduit</h1>
      <p>A place to share your knowledge.</p>
    </div>
  </div>

  <div class="container page">
    <div class="row">

      <div class="col-md-9">
        <div class="feed-toggle">
          <ul class="nav nav-pills outline-active">
            <li v-if='user' class="nav-item">
              <nuxt-link class="nav-link" exact :class="{active: tab === 'your_feed'}" :to="{
                name: 'home',
                query: {
                  tab: 'your_feed'
                }
              }">Your Feed</nuxt-link>
            </li>
            <li class="nav-item">
              <nuxt-link class="nav-link" exact :class="{active: tab === 'global_feed'}" :to="{
                name: 'home',
                query: {
                  tab: 'global_feed'
                }
              }">Global Feed</nuxt-link>
            </li>
            <li v-if="tag" class="nav-item">
              <nuxt-link class="nav-link" exact :class="{active: tab === 'tag'}" :to="{
                name: 'home',
                query: {
                  tab: 'tag',
                  tag: tag
                }
              }">#{{tag}}</nuxt-link>
            </li>
          </ul>
        </div>

        <div class="article-preview" v-for="article in articles" :key="article.slug">
          <div class="article-meta">
            <nuxt-link :to="{
              name: 'profile',
              params: {
                username: article.author.username
              }
            }"><img :src="article.author.image" /></nuxt-link>
            <div class="info">
              <nuxt-link :to="{
                name: 'profile',
                params: {
                  username: article.author.username
                }
              }" class="author">{{article.author.username}}</nuxt-link>
              <span class="date">{{article.createdAt | date('MMM DD, YYYY')}}</span>
            </div>
            <button class="btn btn-outline-primary btn-sm pull-xs-right" :class="{
                active: article.favorited
              }" :disabled="article.favoriteDisabled" @click="onFavorite(article)">
              <i class="ion-heart"></i> {{article.favoritesCount}}
            </button>
          </div>
          <nuxt-link :to="{
            name: 'article',
            params: {
              slug: article.slug
            }
          }" class="preview-link">
            <h1>{{article.title}}</h1>
            <p>{{article.description}}</p>
            <span>Read more...</span>
          </nuxt-link>
        </div>

        <nav>
  <ul class="pagination">

    <li class="page-item" v-for="item in totalPage" :key="item" :class="{active: item === page}">

      <nuxt-link class="page-link" :to="{
        name: 'home',
        query: {
          page: item,
          tag: $route.query.tag,
          tab: tab
        }
      }">{{item}}</nuxt-link>

    </li>

  </ul>
</nav>

      </div>

      <div class="col-md-3">
        <div class="sidebar">
          <p>Popular Tags</p>

          <div class="tag-list">
            <nuxt-link :to="{
              name: 'home',
              query: {
                tag: item,
                tab: 'tag'
              }
            }" class="tag-pill tag-default" v-for="item in tags" :key="item">{{item}}</nuxt-link>
          </div>
        </div>
      </div>

    </div>
  </div>

</div>
</template>
<script>
import { getArticles, getFeedArticles, addFavorite, deleteFavorite } from '@/api/article';
import { getTags } from '@/api/tag';
import { mapState } from 'vuex';

export default {
    name: "HomeIndex",
    async asyncData({ query, store }) {
      const page = Number.parseInt(query.page || 1);
      const limit = 20;
      const { tag } = query;

      const tab = query.tab || 'global_feed';
      const loadArticles = store.state.user && (tab === 'your_feed') ? getFeedArticles : getArticles;

      const [articleRes, tagRes] = await Promise.all([
        loadArticles({
          limit,
          offset: (page - 1) * limit,
          tag
        }),
        getTags()
      ]);

      const { articles, articlesCount } = articleRes.data;
      const { tags } = tagRes.data;

      articles.forEach(article => article.favoriteDisabled = false);

      return {
        articles,
        articlesCount,
        page,
        limit,
        tags,
        tag,
        tab
      }
    },
    watchQuery: ['page', 'tag', 'tab'],
    computed: {
      ...mapState(['user']),
      totalPage() {
        return Math.ceil(this.articlesCount / this.limit);
      }
    },
    methods: {
      async onFavorite(article) {
        article.favoriteDisabled = true;
        if (article.favorited) {
          await deleteFavorite(article.slug);
          article.favorited = false;
          -- article.favoritesCount;
        } else {
          await addFavorite(article.slug);
          article.favorited = true;
          ++article.favoritesCount;
        }

        article.favoriteDisabled = false;
      }
    }
}
</script>
<style>

</style>